Question on gearing..... What rear ratios

springtide9

Hi..

Hopefully a quick question...

Have a compact chainset (50/34) with a 11-23 rear cassette. Pretty new to road cycling.... so just getting used to the gearing.

Been out a couple of times now and very happy with the gearing.. but have noticed that on some of the steeper hills e.g. Rownham Hill, Bristol (the hill on the side of Ashton Court Estate) - I struggle to say in the saddle.

I actually don't mind coming out of the saddle - and once out of the saddle find the climbing enjoyable.. (and not that difficult). I haven't tried pushing through the pain and grinding in the saddle, as there is a less painful option

Half tempted to just keep the gearing the same.. but wondering whether I should get a few more cogs on the back?
With regards to gearing... should you be aiming to be able to ride all hills in the saddle or is coming out of the saddle the norm? (In the UK)

I assume the answer isn't back and white (as if you were in the Alps.. and have a couple of 1000 metres of climbing, you'd not want to be out of the saddle for hours).

Dont think the gearing is that far off, so I assume a 11-26 would be enough. But the obvious disadvantage in swapping is that for ~95% of the rest of the rides - there's a larger spread in the gearing.

I assume thaty unless you ride a triple.. there is no perfect gearing... just a few compromises.

Anyone with any advice? Swap the rear cassette or keep what I have?

rick_chasey

27 on the back would be perfect - an emergency gear.

Ooor, get a 25 and man up a little bit - the more you ride the faster you'll go up.

Oooor, stick with what you have and really man up - take the pain, and harden yourself up.


Either way, climbing hurts A LOT - whatever gear you're in.

John.T

You will seldom need 50/11 so changing to a 12/25 or 12/27 would give better low gears with just the loss of the 11. Your gears from the 12 to the 21 would be the same as you have now.
Short hills can be ridden either in or out of the saddle. Out is more punchy but in is actually more powerful for the same effort. Longer hills need to be ridden mainly in the saddle.

niblue

My bike has 50/34 up front and 11:25 at the back. Never really found that an issue so far but have decided to change to an 11:28 on the back for those times towards the end of a longish ride where it's uphill, into the wind and I'm already tired.

Wife's bike has 50/34 and 11:23 and am changing that to 11:28 as well as she's already complained about the lack of low gears compared to her mountain bike!

alistaird

I'm just building a new road bike and it will be my first compact. Looking at either an 11-27 or 12-27 with a 48/34 on the front (hence the thought of an 11 on the back.)

I'm too old and heavy to live with my current 12-23 and 52/39.

John.T

I can not under stand why you all must have an 11 sprocket. 100 rpm on 50/12 is about 33mph. 50/11 at 100 rpm is only about 3mph faster. Most of you will never push either gear at these revs on the flat and down hill (unless racing) you are better off freewheeling. And if you can not pedal at 100 rpm it is time you learned. 90 is about the easiest for cruising but 100 to 110 should still be comfortable for short bursts.
I would much rather ditch the 11 and get an extra sprocket in the middle of the cassette. This will usually be the 16 which if missing leaves a large gap right where you do not want one.

I'm too old and heavy to live with my current 12-23 and 52/39.

Why. I use that for racing and I am 75kg and 68 years old. I ride 52/38 with 12/27 on my summer road bike and 50/34 with 12/26 on the winter one. You are never too old. But you do slow down though.

geebee2

I assume the answer isn't back and white (as if you were in the Alps.. and have a couple of 1000 metres of climbing, you'd not want to be out of the saddle for hours).

Actually in the Alps although climbs can be very long, they are usually not very steep - roads are well graded with lots of hairpins.

Anyway... I have 50/34 with 11-25.

I think what you have is pretty fine as well though, and 12-25 makes sense as well.

hubba

if it helps i had a 34/50 on the front and a 12/25 on the rear, i changed this for a 11/28 rear cassette and wow what a difference for the long hill climbing sections ! for the better...

but in your case it sunds a little extreme, like some comments you should try at most say a 12/27 or even the 12/25, you still have a nice close ratio of gears with a 12/25 on a 9 speed cassette. (i take it your on 9 speed ??).

i'm sure if you shop around you can get a cheap enough cassette, do a search on my name for post's and you'll see a thread on cassettes with a link to a online shop for a 12/28 rear cassette fr only a mere £20 !!.

springtide9

Thanks for the replies. Interesting and useful comments from all.

Currently have SRAM 10 speed (SRAM PG 1070) 11-23. Looking at SRAM's website, there looks to be a few options.

11, 12, 13, 14, 15, 16, 17, 19, 21, 23
11, 12, 13, 14, 15, 17, 19, 21, 23, 25
11, 12, 13, 14, 15, 17, 19, 21, 23, 26
11, 12, 13, 14, 15, 17, 19, 22, 25, 28
11, 12, 13, 15, 17, 19, 22, 25, 28, 32
12, 13, 14, 15, 16, 17, 19, 21, 23, 25
12, 13, 14, 15, 16, 17, 19, 21, 23, 26
12, 13, 14, 15, 16, 17, 19, 21, 24, 27
12, 13, 14, 15, 16, 17, 19, 21, 24, 28
12, 13, 14, 15, 16, 17, 19, 21, 24, 32

Hadn't really looked up at the gearing for each of the cassettes before, and it's interesting the missing '16' when the largest increases above 23.

I guess I'll need to have a tough session with blowing gales where I'd pay 100s of £ for more teeth on the rear before I finally make a decision ;-)

The 12-25 or 12-26 look the best options... but will see how much the 11 gets used with the 50 first. Top end downhill speed is of no interest really (find it pretty scary when the UK roads have so many huge potholes) ... maybe on my next session I'll keep off the 11 altogether and see how it goes.

Thanks again. Food for thought.

John.T

http://sheldonbrown.com/gears/
This is a useful tool for comparing gear ratios on both rings. whether you set to 'gear inches' or 'gain ratio' is up to you but if the number is the same then so is the gear ratio.
As someone mentioned earlier all gear set ups are a compromise. It is just a case of finding the one that suits you and your riding best.

springtide9

Thanks (John) for the chart/calculator link. Just used it to work out speeds...

Gear chart using MPH @ 100 RPM. For 700 X 25 / 25-622 tire with 175 mm cranks

With 10-speed 11-12-13-14-15-16-17-19-21-23 Cassette

CS CR50 CR34
11 35.7 24.3
12 32.7 22.2
13 30.2 20.5
14 28.0 19.1
15 26.2 17.8
16 24.5 16.7
17 23.1 15.7
19 20.7 14.0
21 18.7 12.7
23 17.1 11.6


With 10-speed 12-13-14-15-16-17-19-21-23-25 Cassette

CS CR50 CR34
12 32.7 22.2
13 30.2 20.5
14 28.0 19.1
15 26.2 17.8
16 24.5 16.7
17 23.1 15.7
19 20.7 14.0
21 18.7 12.7
23 17.1 11.6
25 15.7 10.7


With 10-speed 12-13-14-15-16-17-19-21-24-27 Cassette

CS CR50 CR34
12 32.7 22.2
13 30.2 20.5
14 28.0 19.1
15 26.2 17.8
16 24.5 16.7
17 23.1 15.7
19 20.7 14.0
21 18.7 12.7
24 16.4 11.1
27 14.5 9.9

springtide9

Sorry to bring this up again... thought it was worth asking the question in my previous thread as it has a lot of the info in it already...

I took the plunge and picked up a 11-26 from Wiggle.

Just looking at the cassette, it appears that the three largest cogs are fixed - but the other cogs are interchangeable? Is this correct?

If this is correct (and my other SRAM cassette is the same model), does this mean I can mix and match the rear gearing?

What I'm thinking is... I have two sets of cassettes now:

11, 12, 13, 14, 15, 16, 17, 19, 21, 23
11, 12, 13, 14, 15, 17, 19, 21, 23, 26

(where the bold are fixed)
It's always going to be a compromise, but if I can mix and match I could end up with:

11, 13, 14, 15, 16, 17, 19, 21, 23, 26

Thinking that I'd rather loose a 12 but keep the 16 so that I have the middle ground well covered. Does this work? As in, can I mix and match?

And I guess, if this does work than I also have the option of:

12, 13, 14, 15, 16, 17, 19, 21, 23, 26

John.T

Yes you can mix and match. The gear change may not be as smooth as sprockets are matched to the ones on either side so the chain picks up the new sprocket before it lets go of the old one. The changes to and from the 16 may be a little poorer. I did the same thing with Shimano ones to get a 16 into a 12/27 9sp and it worked fine.
You can not use the 12 as a top gear as the top sprocket is different. It has a shoulder on it. You could fit a 12 top sprocket if you can get one.
I would still have gone for a Shimano 12/27 cassette. I just miss the 18 then. You can not win.

mattshrops

op youre new to cycling but get up the hills ok with a bit of standing up?

sounds to me like as you improve you will probably find that youll stay seated for longer.

if you want the new cassette -fine. if youre not sure , keep on going with what youve got for now. i dont know how steep the hill you mentioned is but if you do a sportive or something with steeper climbs you can always get one then.

springtide9

@John.T : Thanks v much for the confirmation. Just looked at the cassette again and see what you mean with the smallest cog. Sounds like it should just work.

Just looking at the labelling on the cogs themselves - to see if each cog has a teeth value and position on the cassette - but apart form labelling of E10 and F10 (and I can't figure out a pattern), there doesn't appear to be any position labelling - which I guess confirms you should be able to mix and match.

I did have the option for 12/27 with SRAM, but choose against it as I do seem to use the 11 reasonably regularly. I tried restricting myself to 12 - but on those slight slopes, I felt more comfortable (and stable) with a slightly slower rpm - if that makes sense.

But as you say, there will be no perfect setup - you win some and loose some I guess.


@mattshrops : New to road biking, but not to cycling. Have my first Sportive in a months time, and just want that 'get out of jail' cog if the going gets tough (or at the end of the day).
Only on the steepest sections of road do I find myself missing a few cogs, but the Sportive will be my longest (road) ride - plus I'll be cycling to the event (and back) so that the wife gets the car for the day.

Never really thought about gearing on the MTB as I've always run triples. Thanks guys for the info

John.T

One cassette will probably have all the E10 on and the other the F10. Each sprocket will only go on the splines in one place so if you get say a 15 sprocket from each cassette and fit them on the spline you will see that the teeth do not line up. If you look at a cassette you can see that the teeth line up in a nice curve. This is what makes the change smoother. If you stick a 16 into the 15/17 gap you will see this line is broken. Not as bad as it seems but I would not recommend changing when pedalling hard out of the saddle. (Which I never do anyway).

springtide9

Hi John,

I can see what you mean about the pattern of the cogs.... for the 11-26 they are labelled:

11 : E10
12 : F10
13 : G10
14 : B10
15 : F10
17 : F10
19 : E10
21 : B10
23 : NA
26 : NA

But, I can now see that pulling one cog and slipping one in elsewhere will have an impact to shifting.

badflaw

Sorry to Hijack the thread but Im in a very similar position. I run a 34 -25 as my lowest combination and also a mountian biker who astruggles a little..


Would it be easier just to drop to a smaller front ring?

springtide9

badflaw wrote:

Sorry to Hijack the thread but Im in a very similar position. I run a 34 -25 as my lowest combination and also a mountian biker who astruggles a little..

Would it be easier just to drop to a smaller front ring?

Think one of the issues is that 34 is about as small as they go on a double:

http://www.sram.com/sram/road/products/ ... e-crankset
Available Ratios 55/42, 54/42, 53/39 52/38, 52/36, 50/36, 50/34

There is also a big leap from 34 to 50 - which would increase.

John.T

badflaw wrote:

Sorry to Hijack the thread but Im in a very similar position. I run a 34 -25 as my lowest combination and also a mountian biker who astruggles a little..


Would it be easier just to drop to a smaller front ring?

The smallest ring you can fit on a compact chainset is 33 teeth. You would gain more by going to a 12/27 cassette. Or doing both.

John.T

springtide9 wrote:

Hi John,

But, I can now see that pulling one cog and slipping one in elsewhere will have an impact to shifting.

It will have an impact but not disastrously so. I had no problems with mine but did avoid doing power shifts between 15, 16 and 17.

starlet_gt

When it comes to gearing I think a lot of it is psychological, my winter bike is a 53/42 with the biggest cog on the back being a 25 and I sometimes struggle on the steeper climbs, when I'm on my summer bike I have a 50/34 with a 12-25 and still find myself in the 34/25, because I know its there I'll use it...